Fifth wheel trailers and tow vehicles for fifth wheel trailers are generally well known in the art. Fifth wheel trailers are much longer, roomier, and heavier than typical tent campers and travel trailers, and thus a fifth wheel trailer typically requires a specially modified, relatively heavy tow vehicle such as a heavy duty pickup truck. The front portion of a fifth wheel trailer extends over the rear portion of the tow vehicle so that a portion of the trailer's weight is carried over the rear axle of the tow vehicle. In order to accommodate the weight of the trailer, a special hitch assembly is required. The vehicle most commonly used to tow fifth wheel trailers is a pickup truck having an 8 foot bed length.
But, recently, there has been a consumer trend toward extended cab pickup trucks, which have longer, roomier cabs. These trucks have greatly expanded interior cargo volume and also have a second row of seats for accommodating additional passengers. Unfortunately, most of these extended cab pickups are built on a standard wheelbase chassis because consumers prefer the driving characteristics of a shorter truck and, accordingly, the bed of these trucks is typically 6 feet long rather than 8 feet long. Although these shorter bed pickups have the towing capacity to handle fifth wheel trailers, they do not have enough clearance between the axle and the rear of the cab to allow the trailer to pivot to a 90 degree angle without contacting the cab which could damage the truck and severely injure any occupants. In most circumstances, a fifth wheel trailer will contact the cab of a short bed pickup at angles much less than 90 degrees.
One method for allowing a short bed pickup truck to pull a fifth wheel trailer is to use a sliding towing assembly as described in U.S. Pat. No. 6,308,977 ('977 patent). The '977 patent describes a sliding hitch assembly with two main parts, a base assembly and a hitch assembly. The hitch assembly attaches to the hitch pin box of a trailer; the base assembly is mounted in the bed of a vehicle. The sliding towing assembly operates by mechanically sliding the hitch pin rearward from the cab as the trailer pivots. By sliding the hitch rearward, the distance between the hitch pin and the cab increases during turns, thereby allowing turns up to 90 degrees without the trailer contacting the cab.
This aforedescribed hitch assembly can be improved upon. First, the contact between the slide plate and the guide rails causes friction and noise as the hitch assembly slides. Friction can lead to stress or strain on the components of the hitch assembly, and noise from the hitch assembly can cause discomfort or annoyance to the driver and passengers, as well as a perception of low quality construction. Second, when the truck and the trailer are aligned and the truck accelerates or decelerates the slide plate has a tendency to rock or slide.
Accordingly, there exists a need for an improved sliding towing assembly that allows fifth wheel trailers to be towed using short bed pickup trucks, but minimizes noise and friction during turning. There also exists a need to minimize hitch movement during acceleration and deceleration when the trailer and vehicle are aligned.